Chain drives are used in association with vehicle engines to drive such ancillary components as valve lifters. Often, chain drive assemblies are designed to capture dripping and/or splashing oil from the engine oil sump for lubrication of those assemblies. However, where splash or drips from the engine sump are insufficient and/or where bearings are too far away from the engine, the bearings may be deprived of adequate lubricating oil. In addition, the structure of the chain drive assembly or the presence of assembly components such as seals or assembly retention features may block oil from reaching the bearings.
Pump systems, either separate pumps used with the chain drive assemblies or those diverting oil from the engine pump to the chain drive assembly may be used to provide the necessary quantity of oil to the assembly. However, these systems add to the overall cost of the vehicle and can increase the complexity of the design, e.g. in fitting additional components into the engine compartment.
Thus, there is a need in the field to provide an inexpensive method and apparatus to adequately lubricate chain drive sprocket assemblies used with engines in vehicles.